i think that all your distress is the result of the fact that you are believing something which your mind knows is untrue. deep down your subconscious can't accept that there is no God because it's imbedded into you that there is. God says in the Holy Quran, Chapter 7, that he created all our souls and asked them "Am I not your Lord" and they all replied that He was our Lord. and this information is recorded into our subconscious. it's a memory although we don't remember at conscious level. so anything belief contrary to this truth will not be accepted by our subconscious and we will always question that belief. for example, I, a believer in One God, don't ask myself what is the proof that there is God? is there God? how do i know that there is one God or more Gods, etc. That is because my subconscious is satisfied with my belief. athiests and agnostics on the other hand are not at peace with their beliefs and therefore always try to prove if there is God or not.
so your solution is really simple: just believe that there is God and your mind will satisfied. afterall, how can there not be God? If there isn't God, then who created the universe? if everything evolved one from the other, then who created the first particle? and who caused it to evolve? etc etc. everything around us prove the existence of God: all the animals, humans, vegetables, day and night, unlimited supply of oxygen in the atmosphere, rain, the solar system and the position of planets, etc etc all prove that there is God, that there is just One Creator, and that this Creator is very Wise and Very Kind.
once you accept the truth, your mind will be at ease and then you can further study Islam to see whether it is the True religion or not.
as for your disorder, do get medication, but i'm hopeful that once you come to correct faith about God and start studying Islam with an open mind, your mind will get better by itself.
May God help you and show you the truth. You can read translation of the Quran at
http://quran.com/
Verse 172-174 from Chapter 7:
And [mention] when your Lord took from the children of Adam - from their loins - their descendants and made them testify of themselves, [saying to them], "Am I not your Lord?" They said, "Yes, we have testified." [This] - lest you should say on the day of Resurrection, "Indeed, we were of this unaware."
Or [lest] you say, "It was only that our fathers associated [others in worship] with Allah before, and we were but descendants after them. Then would You destroy us for what the falsifiers have done?"
And thus do We [explain in] detail the verses, and perhaps they will return.